Comment 2 for bug 1541482

I can reproduce this. Here's a simple repro:

juju bootstrap ...

juju deploy --series trusty ~/canonical/repository/trusty/ubuntu
# Wait for deploy to finish (perhaps not necessary)

juju create-model foo

# Make a trivial change to the charm but *don't* bump the charm
# revision. Changing the description text is enough.

juju deploy --series trusty ~/canonical/repository/trusty/ubuntu

# When the new unit agent comes up, the uniter will fail with the hash
# mismatch error.

Digging more...